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Abstract: FR-PO1132

Clinicopathological Discrimination of Primary and Genetic Focal Segmental Glomerulosclerosis in Children

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Ishizuka, Kiyonobu, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Harita, Yutaka, Dept. of Pediatrics, Tokyo University, Tokyo, Japan
  • Iida, Takaya, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Nagasawa, Takeshi, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Ban, Hideki, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Shirai, Yoko, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Yabuuchi, Tomoo, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Kaneko, Naoto, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Miura, Kenichiro, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
  • Hashimoto, Taeko, Yamagata University, Yamagata-city, Japan
  • Hattori, Motoshi, Tokyo Women's Medical University, Shinjuku-ku, Tokyo, Japan
Background

(Background) FSGS is classified as primary FSGS caused by unidentified humoral factor(s) and secondary FSGS including genetic abnormalities, and the cause of the disease of each patient has crucial implication on treatment strategies and renal transplant success. Sethi S, et al. described that >80% foot process effacement covering glomerular surface area is suggestive of primary form in adult FSGS by comparing nephrotic patients with non-nephrotic ones (Nephrol Dial Transplant, 2015). However, it is known that nephrotic syndrome can be observed not only in primary form but genetic one in children. Therefore, we conducted a clinicopathological study comparing clinically proven primary FSGS with genetic FSGS.

Methods

Pediatric FSGS patients (10 primary and 8 genetic) who progressed to ESRD and underwent renal transplantation were included in this study. All the primary FSGS patients had posttransplant recurrence, and all the patients with genetic FSGS carried pathogenic mutations and did not have posttransplant recurrence. We retrospectively analyzed their clinical course and histology of the native kidneys before transplantation. The degree of foot process effacement (FE) of podocytes was calculated as the ratio of the FE area on capillary loops to glomerular surface area.

Results

There were no differences between primary and genetic FSGS on age at onset (5.5 ± 3.0 years, 4.6 ± 3.0 years) and the period from onset to ESRD (5.5 ± 4 years, 4.5 ± 3.5 years). The period from onset to kidney biopsy was significantly shorter in genetic than primary FSGS (0.7 ± 1.4 years vs 3.4 ± 3.4 years) (p = 0.02). The rate of nephrosis at onset, and of edema observed during the course, and of the initial responsiveness to steroid treatment were all significantly higher in primary FSGS (p <0.01). Serum total protein (TP) at the time of kidney biopsy was significantly lower in primary FSGS (3.7 ± 0.6 g / dl vs 5.3 ± 1.1 g / dl) (p <0.01) with TP above 3.9 g/dl predicting genetic (sensitivity 100%; specificity 75%; AUC 0.927). The percentage of FE at 80% completely discriminated primary from genetic cases (98 ± 6% vs 61 ± 12%).

Conclusion

Discrimination between primary and genetic FSGS could be possible by integrating the pathological findings with clinical information.